Switches are widely used in, for example, automotive applications to drive different types of loads, for example, motors, relays, bulbs, LED modules for interior and exterior lighting, etc. A microcontroller monitors the operation of these different types of loads. The microcontroller protects the integrated circuits against overloading and initiates suitable measures in the case of an electrical overload. For this purpose, the current flow through a corresponding circuit, in particular a power semiconductor device, is usually detected and compared with predetermined values. Although the switches are protected internally against electrical over stress, the microcontroller receives the current flow information to apply a further protection strategy.
The micro controller adjusts the operation of various components based on the current flowing through a sensor circuit. Under certain operating conditions, called inverse conditions, large flow of current through the sensor circuitry is possible resulting in erroneous measurements by the micro controller. Such erroneous measurements can result in an incorrect response from the micro controller. During inverse conditions, the current through the sensor circuit is disturbed and, as a consequence, the microcontroller receives incorrect information.
Hence, what are needed are means to minimize measurement errors during adverse operating conditions.